1. Technical Field
The present invention relates to a sheet supply device to be provided in an image forming apparatus.
2. Background Arts
Generally, an image forming apparatus such as a stencil printing machine includes a sheet supply device for supplying print sheets to an image forming unit. Such a sheet supply device includes a sheet supply tray on which print sheets are stacked. An entire of a sheet supply tray can be retracted-into and drawn-from a main body of the apparatus. Alternatively, a portion of a sheet supply tray may be extended outward from an opening of a main body of the apparatus.
Such a sheet supply device includes a guide fence(s) for restricting positions of print sheets along a sheet width direction perpendicular to a sheet supply direction. The guide fence(s) can be moved manually along the sheet width direction according to a size of print sheets. In addition, the sheet supply device also includes a guide fence mechanism for locking the guide fence(s).
Various types of lock mechanisms are proposed. For example, Japanese Utility Model Application Laid-Open No. H6-72995 discloses a guide fence mechanism for a pair of guide fences that regulates a width between side edges of print sheets stacked on a sheet supply tray. The guide fences can be moved independently from each other. Each of the guide fences is provided with a lock lever having an eccentric cam. Movement of each of the guide fences is restricted when the lock lever is operated.